I Am a Grammar Nazi, and while I do apologize for offense taken, I am afraid I shall not be changing my ways., but I will happily answer your question.
I do it simply because I am so passionate about the English language. It is beauty, it is connection, it is life itself because it is the means I use for almost all my communication (intentional, anyway: I also communicate via body language, facial expression and non-verbal tones and sounds, but most of that is not concious), and communication is crucial to my emotional and mental health, my spiritual and intellectual growth, and my pleasure. I cherish the precision and variety of it, I relish the charm, artistry and power.
Unfortunately, the more people who speak and write poorly, the more speaking and writing poorly is accepted, and therefore the more degraded the language becomes. Meanings become lost in lazy speech, which robs the language of it’s precision at first, and eventually the rest is lost as well. Compare the way an average modern college graduate speaks and writes with the way the average person who had completed 9th grade spoke and wrote 150 years ago and you will see what I mean.
Not that I am trying to freeze the language, I understand that it is a living thing that is always changing. But not all change is for the better.
So my little corrections here and there are simply my own tiny (almost certainly futile) efforts to preserve the clarity and beauty of the language I love so well.
How’s that?
(Current Grammar Nazi peeve, since it has seeped so far into the language that I fear it will never be rooted out and it grates on me every. single. time…“continue on” - if you are stumped, think about it: redundant. I really dislike redundancy. One may “go on” or one may “continue”, but “continuing on” is in the same sorry category as “with au jus”, which means “with with juice”.
Out of the many thousands of posts I have written for this joint, one of my favorites was a grammar rant titled “Less semen, fewer sperm, bloody hell!”: I like to think it contributed a little to saving that distinction. Again, if you are stumped: it’s less of a single thing, fewer many things: less money/fewer dollars, less food/fewer meals, etc. One of the reasons I love Trader Joes is because most of the ones I frequent have signs which read, “10 items or FEWER” ahhhh… )